Services and References
Applications interact via services and references. A service is a set of operations and the messages required by the operations. A reference identifies the service consumed by a component or composite. Applications offer services and invoke references to other services.
An application's services and references are promoted from the services and references of the components it contains.
Component services can be consumed by other components within the composite or promoted as composite services for use by consumers outside the composite. A composite service has an interface and one or more bindings.
Component references consume services provided by other components in the same composite or services provided outside the composite. A composite reference has an interface and one binding.